1. Field of the Invention
The present invention relates to a recursive path computation method capable of automatically allocating lower layer resources to process a path request when resources required for path computation by layers is not sufficient or have not previously allocated by collectively or integratedly managing resources required for computing a data transmission path in a multi-layer transport network.
2. Description of the Related Art
A multi-layer transport network is a network including networks such as light, TDM, Ethernet, and the like, and diverse equipments each having a different data transmission scheme and switching capacity. Those equipments constituting the multi-layer transport network may provide transmission resources of multiple layers and perform inter-layer switching in data transmission.
In order to provide a transmission service, the related art multi-layer transport network manages resources by layers. Namely, each management and control system is provided for each layer, and a transmission service is separately operated by each operating subject.
However, recently, as the market demand for a light/packet integrated transport network is increasing and development of relevant equipments is actively ongoing, an integrated resource management function different from those conventional techniques is required. Namely, as light/packet transmission layer-integrated equipments are put on the market, a method for computing a path for a transmission service is required in the multi-layer resource network using an integrated equipment.
In the related art path computation method of the multi-layer transport network, resources required for each layer are predicted in advance and allocated to each layer to establish a requested packet or light/TDM transmission path. For example, resources required for a path computation are allocated in units of lambda in each layer, which are then managed by a traffic engineering (TE) link. Thus, in the related art, when a path computation request for a transmission service of each layer is received, a path is computed by layers by utilizing the already allocated TE link resources.
The related art management method, however, has a problem in that if the TE link resources previously allocated by layers are not sufficient, an operator should additionally set a required resource for a corresponding layer. In addition, a situation in which one layer is in short of resources because of congested path requests while another layer does not have a path request only to result in a waste of the previously allocated resources is inevitable. Thus, the related art has a limitation in real-time computation of paths or in utilizing resources required for path computation.